// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/threading/platform_thread_internal_posix.h"

#include "base/containers/adapters.h"
#include "base/logging.h"

namespace base {

namespace internal {

    int ThreadPriorityToNiceValue(ThreadPriority priority)
    {
        for (const auto& pair : kThreadPriorityToNiceValueMap) {
            if (pair.priority == priority)
                return pair.nice_value;
        }
        NOTREACHED() << "Unknown ThreadPriority";
        return 0;
    }

    ThreadPriority NiceValueToThreadPriority(int nice_value)
    {
        // Try to find a priority that best describes |nice_value|. If there isn't
        // an exact match, this method returns the closest priority whose nice value
        // is higher (lower priority) than |nice_value|.
        for (const auto& pair : Reversed(kThreadPriorityToNiceValueMap)) {
            if (pair.nice_value >= nice_value)
                return pair.priority;
        }

        // Reaching here means |nice_value| is more than any of the defined
        // priorities. The lowest priority is suitable in this case.
        return ThreadPriority::BACKGROUND;
    }

} // namespace internal

} // namespace base
